1. Field of the Invention
The present invention relates to pest deterrents and high frequency sonic generators. More specifically, the present invention relates to an electrical device for emitting an ultrasonic sound to drive away pests from a given area, preventing them from infesting or consuming crops and vegetation.
Grasshoppers and other insects can devastate a greenhouse or garden in a short amount of time by consuming its edible vegetation, stunting growth of the plants or killing them entirely. Insects of this type can infest and devour large volumes of plant life, wherein their removal is difficult and time consuming. Similar to insect pests, larger herbivores such as voles and birds can pose a threat to an individual's plant vegetation by consuming large quantities thereof. To remedy this common problem, homeowners and farmers generally utilize toxic insecticides or traps to kill and keep pests away. However, these insecticides tend to include harsh chemicals that may be potentially harmful to household animals or damage the food or plants themselves. Besides being dangerous, pesticides can also be expensive and traps can prove ineffective with respect to larger infestations of ground rodents and vermin. A more effective solution to this problem is therefore required, wherein the solution does not pose harm to the plants themselves and is more broadly effective.
It is well understood that certain insects and animals have the ability to perceive ultrasonic sounds beyond the range of human hearing, whereby these animals are capable of receiving or transmitting sound waves in excess of 20 kHz. It is further submitted that certain signals within the ultrasonic spectrum, being of particular pitch, tone and intensity, can be particularly annoying or even painful for certain species of animals. Evidence of this is seen in the application of dog whistles, wherein an ultrasonic whistle transmits sound waves above human hearing levels to communicate or inflict pain on the dog for training, attention grabbing or obedience purposes. In a similar fashion, ultrasonic sound generators have been produced that emit sound waves in the ultrasonic range for deterring certain animals and pests from a given area. These devices include a number of differing structures and components for the purposes of creating an ultrasonic sound; however most lack the ability to sweep through a chosen set of frequency bands to ward off particular pests, while also not affecting animals such as household dogs and cats in the process.
The present invention is submitted as a means to deter pests using an ultrasonic sound emitter having a switchable set of frequency bands, a means to sweep across a broad or narrow set of frequencies, and a means of ensuring continued operation of the device through visual and auditory means. The device of the invention comprises a water resistant housing having a speaker transducer, wherein ultrasonic sound waves are generated as a passive means of dispersing pests and deterring their willingness to infest a given area. This allows homeowners to safely keep grasshoppers, voles and other pests away from their greenhouses, gardens and fields, wherein a frequency band found most suitable for given pest is chosen for operation. The device may be mounted on the inside of a greenhouse, receive outlet or battery power and will automatically turn itself on and off over certain intervals. This eliminates the need for insecticide poisons or traps, uses very little power and can be used year-round with little maintenance.
2. Description of the Prior Art
Devices have been disclosed in the prior art that relate to pest deterrent and ultrasonic signal generating devices. These include devices that have been patented and published in patent application publications. The forgoing is a list of devices deemed most relevant to the present disclosure, which are herein described for the purposes of highlighting and differentiating the unique aspects of the present invention, and further highlighting the drawbacks existing in the prior art.
Specifically, U.S. Pat. No. 4,562,561 to Ackley is one such device that discloses an electrical apparatus for repelling animal and insect pests using an ultrasonic signal that is pulsed or swept across a frequency range, wherein the ultrasonic receptors of the pests are disrupted and the pests are driven away from the signal source. A first, second and third signal are disclosed, along with a means for modulating the selected signal. The first signal includes a fundamental frequency of 22 kHz, the second signal having a pair of fundamental frequencies of approximately 22 and 35 kHz, and the third signal having a plurality of fundamental frequencies in the range of 18 kHz to 33 kHz. A means of sweeping through the fundamental frequencies is built into the circuit, while an ultrasonic transducer outputs the signal from the circuit. The Ackley device, while disclosing a signal generator as a means of deterring pests, fails to disclose many of the key features inherent in the present invention, including the construction of the overall assembly, along with the options provided by the present circuit board design that allow four separate tone frequencies and a means of establishing a consistent narrow or broad range frequency sweep during operation. The ability to test the operation of the device using a frequency within human hearing range is further not disclosed by Ackley.
U.S. Pat. No. 3,838,418 to Brown is another such device, where a pest control apparatus is disclosed having a tone generator create an output frequency as a function of applied voltage, along with a transducer for outputting the signal. The tone generator includes a means of providing an interrupted, slop saw-tooth output having a continuously changing frequency between intervals of constant tone frequency. A gating means for chopping the output tone into changing frequency periods interspersed with output rest periods. The Brown device is adapted for dispersing mice and rats using an ultrasonic sound wave that modulates frequency with a secondary modulation of pitch. Periodic bursts of high intensity ultrasonic sound are intervened by rest periods, which prolongs the life of the transducer when compared with continuous operation, while remaining effective for its intended purpose. While similarly using an ultrasonic noise source to cause pests to flee, the Brown device provides a means of modulating pitch for increasing the coefficient of annoyance. Its design elements and intent differ from that of the present invention.
Further, U.S. Pat. No. 4,999,818 to Malleolo discloses a circuit for producing ultrasonic signals for repelling pests and vermin. The device comprises a transducer for producing ultrasonic signals, an audio amplifier, and an oscillator having at least a first and second multivibrator means. The oscillator includes a variable resistance network for adjusting the frequency thereof using an operable switch to choose a particular frequency. The transducer is preferably an acoustic speaker with a frequency range between 22 kHz and 50 kHz. The Malleolo device offers a variable resistance network as a means of choosing the output signal. Similar to the Brown and Ackley, the design elements and operation of Malleolo differ from that of the present invention.
U.S. Pat. No. 7,324,408 to Cilliers discloses another pest repelling device installed within a vehicle, wherein the device is adapted to deter rodents and insects from entering and nesting within the engine compartment of a motor vehicle. The device comprises a control unit and a plurality of transducers adapted to connect to the control unit to provide a random sweep between 1 millisecond and 1 second bursts between a lower frequency of 20 kHz and an upper frequency of 45 kHz. The Cilliers device is one that is adapted to be utilized in conjunction with a motor vehicle and be housed within the engine bay compartment, which can be prone to bird and rodent nests over time, and in particular if the vehicle is left parked outdoors for extended periods. The construction and intent of the Cilliers device diverges from that of the present invention, which is designed for greenhouses and outdoor use, and includes a different circuit design and application of ultrasonic sound for pest deterrence.
Finally, U.S. Pat. No. 6,166,996 to Grissom discloses an ultrasonic broadband frequency transducer for pest repulsion, wherein the device comprises a variable frequency generator, at least one ultrasonic frequency amplifier, and a transponder unit comprising at least two transducers. The device is adapted to address the directional and attenuation problems with existing pest repulsion transducers, wherein most existing devices utilize a single frequency transducer that is centered about a center frequency and whose response curve sharply drops off moving away from this frequency. The Grissom device contemplates utilizing several transducers or speakers for a more effective device having a broader effective frequency response curve. The present invention provides a single transducer, however the elements and functions of the present invention differ significantly in design elements and in intent from the Grissom device.
The present invention is designed to utilized sound technology to rid greenhouses and gardens of unwanted pests. The device emits a sweeping high frequency sound wave, above the human hearing range, that is painful or annoying for insects and rodents to bear at close range. The invention includes four main components: a housing unit, a circuit card assembly, a signal transducer and a power supply module. The circuit design creates sweep frequencies applied to a driver section that drives the transducer, which is preferably a piezo power speaker. The circuit allows a narrow or broadband sweep is provided, along with a confidence tester signal generator for emitting sound in the human hearing range. It is submitted that the present invention is substantially divergent in design elements from the prior art, and consequently it is clear that there is a need in the art for an improvement to existing ultrasonic pest deterrent devices. In this regard the present invention substantially fulfills these needs.